Conventionally, there is provided a power cord having a plug, a thermal sensor, and a cut-off means (for example, Japanese Patent Application Publication No. 7-67245 A). The plug is configured to be connected to an electrical outlet (or socket). The thermal sensor is configured to detect (measure) a temperature of the plug. The cut-off means is configured to stop electric power from being supplied from the plug side to a load when an abnormal rise in temperature is detected with the thermal sensor. The plug has blades configured to be inserted into the electrical outlet to come into contact with receptacle contacts in the electrical outlet, respectively.
In this sort of power cord, even in the case of abnormal heat generation due to contact failure between the electrical outlet and the blades of the plug, it is possible to protect the plug from the abnormal heat by stopping electricity feeding.
In the power cord including only one thermal sensor, there is a concern that safety is impaired by a delay in response to a temperature rise of a blade caused by a comparatively low correlation between the blade, furthest from the thermal sensor, of the blades of the plug and an output of the thermal sensor.